A technology disclosed herein relates to management of a storage system, and more particularly, to an extension of a storage capacity of a storage system.
Conventionally, in order to securely store data used by companies and the like, storage systems configured into the redundant array of inexpensive disks (RAID) are widely used. The quantity of the data stored in these storage systems is explosively increasing, and it is thus necessary to extend the storage capacity of the storage system by adding disk drives. Generally, disk drives are added for respective RAID groups. For example, if the RAID level 5 that has a configuration of 3D (data)+1P (parity) is applied, four disk drives constitute one RAID group. In this case, in order to carry out an addition of disk drives once, at least four disk drives are necessary.
JP 07-141121 A discloses a technology for extending a storage capacity by extending a data width of a RAID group. According to this technology, when the RAID level 5 having the 3D+1P configuration is applied, by adding one disk drive to the RAID group, the configuration thereof is changed to 4D+1P. As a result, it is possible to add one disk drive at a time, and an extension of the storage capacity with the minimum necessary cost is thus realized.